Exposure of the general public to RF electromagnetic fields

Transcription

Workshop "Acute Health Impairment", Dec 12-13, 2006
Exposure of the general public
to RF electromagnetic fields
Dr. Christian Bornkessel, IMST GmbH,
Carl-Friedrich-Gauss-St. 2, D-47475 Kamp-Lintfort
bornkessel@imst.de
IMST GmbH
Carl-Friedrich-Gauß-Strasse 2
47475 Kamp-Lintfort
www.imst.de
Tel.:
Fax:
E-Mail:
+49-2842-981-0
+49-2842-981-199
contact@imst.de
Outline
• RF sources and their exposure
- relevant exposures in everyday life
- focus on general public exposure
- exposure results with special regard to DMF studies
• Personal exposure meters (Dosimeter)
- available dosimeters
- typical results
Folie 2
Exposure of general public, November 07
Classification of relevant RF sources
Installation type
Fixed
Mobile
Mobile phone
base stations
Mobile phones
TV broadcast
transmitters
DECT phones
Radio broadcast
transmitters
WLAN applications
Folie 3
Installation place
Outdoor
Household
Mobile phone
base stations
Mobile phones
TV broadcast
transmitters
DECT phones
Radio broadcast
transmitters
WLAN applications
Folie 4
Distance
Far field
Close to body
or body contact
Mobile phone
base stations
Mobile phones
TV broadcast
transmitters
DECT phones
Radio broadcast
transmitters
WLAN applications
Folie 5
Mobile phone base stations
Frequency: - 925 – 960 MHz (GSM 900)
- 1820 – 1880 MHz (GSM 1800)
- 2110 – 2170 MHz (UMTS)
Transmit
Power:
- typ. 5-30 W/channel/sector
- 100-1800 W (EIRP)/channel/sector
Transmitter: - ~85,000 stations in Germany
Coverage: - 500 m – 20 km
Distance to
Persons:
- far field
Remarks:
Folie 6
- power control
Projects supported within DMF
Development of measurement and calculation
methods for the determination of the public
exposure due to electromagnetic fields in the
vicinity of mobile phone base stations (IMST)
Determination of the exposure of groups of
people that will be investigated within the scope
of the project "Cross sectional study for
ascertainment and assessment of possible
adverse effects by fields of mobile phone base
stations" (ECOLOG)
Determination of the real field distribution from
high frequency electromagnetic fields near
UMTS transmitters (IMST+EM Institute)
Folie 7
BS
Extrapolated exposure (IMST+EM-Institute)
100,000
1.6 % limit
5.4 V/m
78.3 mW/m²
GSM
power density in % of limit
10,000
UMTS
0.7 % limit
5.1 V/m
69.3 mW/m²
1,000
0,100
0,010
0,001
0,000
1
2
3
4
0.000001 %
0.004 V/m
0.03 µW/m²
Folie 8
5
6
scenario no.
7
8
9
0.000001 %
0.01 V/m
0.1 µW/m²
10
11
Extrapolated exposure near base stations (2)
100,000
high mounted antennas
GSM
power density in % of limit
10,000
UMTS
1,000
0,100
0,010
0,001
0,000
1
2
3
4
5
6
7
8
9
10
11
scenario no.
low mounted antennas
Folie 9
low mounted antennas
(micro cell / indoor scenarios)
14
12
10
8
6
4
2
0
GSM
UMTS
measurement point no.
GSM 900 antenna pattern
1.1
1.2
1.3
1.4
1.5
1.6
1.7
1.8
1.9
1.10
1.11
1.12
1.13
1.14
1.15
1.16
1.17
1.18
1.19
1.20
1.21
1.22
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
2.10
2.11
2.12
3.1
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
3.11
3.22
3.13
3.14
3.15
3.16
3.17
¾ GSM > UMTS at
85 % of all points
(compared to limit)
UMTS antenna pattern
4.1
4.2
4.3
4.4
4.5
4.6
4.7
4.8
Comparison GSM/UMTS
Folie 10
electric field strength [% of limit]
Small scale field variation in space
Measurement: GSM 900 and UMTS
Simulation: GSM 900
electric field strength [dBµV/m]
100
95
90
85
80
75
GSM 900
UMTS
70
0
20
40
60
80
100
120
140
place [cm]
• Small scale variations (fast fading) especially at indoor scenarios
due to multipath propagation
• Variations of 10 dB and more
Folie 11
Small and large scale variations in time
Station A: GSM 24 hours
Station B: GSM 7 days
2.0
electric field strength [V/m]
electric field strength [V/m]
4
3,5
3
2,5
2
1,5
1
12:00
1.8
1.6
1.4
1.2
1.0
16:00
20:00
0:00
time
4:00
8:00
12:00
Tu
We
Th
Fr
Sa
Su
day
• Small and large scale variations due to traffic load (power control)
Folie 12
Mo
Tu
Time and space averaged exposure (ECOLOG)
Exposure inside buildings
1 m x 1 m grid
5 point grid
• Time and space averaging, no focus on "maximal exposed areas"
¾ Exposure 10 - 1,000 times smaller than measured under worst case aspects
Folie 13
Source: ECOLOG Institute
Mobile phones
Frequency: - 880 – 915 MHz (GSM 900)
- 1710 – 1785 MHz (GSM 1800)
- 1920 – 1980 MHz (UMTS)
Transmit
Power:
- up to 250 mW time averaged
- up to 2 W peak
Number:
- ~80 million
Coverage: - up to 20 km
Distance to
Persons:
- body contact
Source:
www.sonyericsson.com
Folie 14
Remarks:
- power control
2
1,8
1,6
1,4
1,2
1
0,8
0,6
0,4
0,2
0
Sony Ericsson W550i
Nokia E50
Nokia 6230i
Sony Ericsson W700i
Nokia 3250
Sony Ericsson K750i
Sony Ericsson W810i
Nokia 6233
Nokia 6270
Nokia 6131
Mobile phone
• SAR is measured under "worst case" conditions
(maximal transmit power)
• typ. 10 – 75 % limit consumption
Nokia N93
Nokia N73
Sony Ericsson K510i
Sony Ericsson W800i
Nokia 6125
LG U8290
Samsung SGH-E770
Samsung SGH-X700
Siemens S75
Motorola ROKR
Sagem my 700X
BenQ-Siemens C81
BenQ-Siemens EF81
Motorola L7
Motorola V3x
Pantech GU-1100
Palm Treo 650
SAR-Measurements
Folie 15
SAR value 10g [W/kg]
Determination of the specific absorption
rate (SAR values) occurring during dayto-day mobile phone use
(Telecom-Consult)
Determination of the real exposure from
using mobile phones in partially shielded
rooms as compared to exposure under
optimal conditions outdoors
(Telecom-Consult)
Folie 16
Source: Telecom-Consult
Exposure results: Averaged exposure
Inside a room, Nokia 6150
Inside a train, Nokia 6110/6150
Position change
• On average 10 – 50 % of "worst case" SAR, depending on
coverage and cell changes
• Further reduction due to DTX
Folie 17
Source: Telecom-Consult
TV Broadcast
Frequency: - 47 – 68 MHz (analogue)
- 174 – 223 MHz (analogue, digital)
- 470 – 790 MHz (analogue, digital)
- 790 – 862 MHz (digital)
Transmit
Power:
- up to several 100 kW (ERP)
per site
Transmitter: - typ. 5-15 main transmitters
each federal state (Germany)
Wendelstein
Folie 18
Distance to
Persons:
- far field
Determination of exposure
to the population living near
digital radio and television
transmitters
(IMST+EM Institute)
Folie 19
Exposure to Analogue TV and DVB-T (same region)
DVB-T
100
100
10
10
power density [% of limit]
Analogue TV
1
0,1
0,01
0,001
0,0001
0,00001
1
0,1
0,01
0,001
0,0001
0,00001
0,000001
0,000001
0
50
100
150
200
250
300
350
0
measurement point
50
100
150
200
250
measurement point
• More than 300 measurement points in Nuremberg and Munich region
• Points statistically distributed; proportional to population density
• Measurements before (A-TV) and after (DVB-T) switching to DVB-T
¾ Exposures mostly below 0.01 – 0.1 % of limit
Folie 20
300
350
FM radio and DAB
Frequency: - 88 – 108 MHz (FM radio)
- 174 – 223 MHz (DAB)
- 1452 – 1492 MHz (DAB)
Transmit
Power:
- FM: typ. several 10 kW (ERP)
DAB: typ. several kW per site
Transmitter: - several 100 (Germany)
Distance to
Persons:
- far field
www.zinsik.de
Folie 21
Determination of exposure
to the population living near
digital radio and television
transmitters
(IMST+EM Institute)
Hamburg
Berlin
Düsseldorf
Stuttgart
München
Folie 22
Exposure to FM radio and DAB (same region)
DAB
100
100
10
10
FM radio
1
0,1
0,01
0,001
0,0001
0,00001
1
0,1
0,01
0,001
0,0001
0,00001
0,000001
0,000001
0
50
100
150
200
250
300
0
measurement point
50
100
150
200
measurement point
• 300 measurement points in Nuremberg and Munich region
• Points statistically distributed; proportional to population density
¾ Exposures mostly below 0.01 – 0.1 % of limit
¾ DAB exhibits ~11 dB lower exposure compared to FM radio (median)
Folie 23
250
300
Long/Medium/Shortwave radio services
Frequency: - 148 – 255 kHz (LW)
- 0.526 – 1.6 MHz (MW)
- 3.4 – 26 MHz (SW)
Transmit
Power:
- several 100 kW per site
(up to 2 MW)
Transmitter: - several 10 (Germany)
Coverage: - several 100 km
Distance to
Persons:
- far field
Folie 24
Exposure results
Study by Wuschek et al., 2003
"Large area measurement of radio waves in Baden-Wurttemberg"
100
(electric field strength)² [% of limit])² .
10
1
0,1
0,01
0,001
0,0001
1001
1052
1106
1156
2041
2092
2142
2193
2243
2293
2343
2393
2443
2493
2543
3014
3064
4037
measurement point
• 895 points, regular 2 x 2 km grid, outdoor
¾ Exposure may reach or exceed GSM/UMTS exposure near to base stations!
Folie 25
Wireless LAN (IEEE 802.11b)
Frequency: - 2400 – 2483.5 MHz
Transmit
power:
- max. 100 mW EIRP
Transmitter: - several 100,000
Coverage: - several 10 meter
Distance to - access points: far field
Persons:
- mobile: close to body
or body contact
Remarks:
Folie 26
- power control by duty cycle
Determination of human
exposure caused by indoor
wireless communication
technologies applied in
homes and offices
(ARC Seibersdorf Research)
Determination the real field
distribution of high frequency
electromagnetic fields near
wireless LAN installations
(WLAN) in inner cities
Folie 27
Source: ARC Seibersdorf Research
Exposure results (time and space averaged)
0.01
0.001
0.0001
power density [mW/m²]
0.1
0.00001
distance [m]
• outdoor scenarios: typ. 10-11 – 0.001 %
• indoor scenarios: up to 0.1 %
• close to body operation: typ. 2 - 3 % of SAR-limit
Folie 28
Digital cordless phones: DECT
Frequency: - 1880 - 1900 MHz
Transmit
power:
- max. 250 mW peak power
Transmitter: - several 100,000
Coverage: - several 10 meter
Distance to - base station: far field
Persons:
- mobile: body contact
Remarks:
Folie 29
- power control by duty cycle
Determination of human exposure
caused by indoor wireless
communication technologies applied
in homes and offices
Results: time and space averaged in % of limit
• 2 DECT devices, 1 and 3 m:
BS: 0.004 – 0.03 %,
MS: 0.0002 – 0.004 %
• SAR10g: 0.6 – 8 %
• generic scenarios: 0.00007 – 0.0003 %
• mixed scenarios: 0.00007 – 0.023 %
Folie 30
base stations
averaged
mobile phones
(SAR) worst case
mobile phones daily
life
radio service
analogue TV
DVB-T
FM radio
DAB
LMS radio
body contact
DECT
close to body
WLAN
100
10
1
0,1
0,01
0,001
0,0001
0,00001
0,000001
base stations worst
case
Putting all results together ...
Folie 31
limit consumption [% of power limit]
... the same with median
limit consumption [% of power limit]
100
body contact
10
1
close to body
0,1
0,01
indoor
0,001
0,0001
0,00001
Folie 32
radio service
DECT
WLAN
LMS radio
DAB
FM radio
DVB-T
analogue TV
mobile phones daily
life
mobile phones
(SAR) worst case
base stations
averaged
0,000001
base stations worst
case
outdoor
median
Be carefully with your interpretation!!!
Personal exposure meters (Dosimeters)
Maschek ESM-140
www.maschek.de
Folie 33
Antennessa EME Spy 120
TV3
Tetra
TV4&5
GSM Tx
Problems with cross-talk
GSM Rx
GSM Rx
GSM Rx
DCS Tx
DCS Rx
DCS Rx
DCS RX
DECT
UMTS Tx
UMTS Rx
UMTS Rx
UMTS Rx
WIFI
Frequency bands Antennessa
Folie 34
FM
Measurement with "extra" exposure
GSM/UMTS base
station, 350 m
Folie 35
Microwave oven,
30 cm
Mobile phone,
70 cm
"Normal" situation
Folie 36
Dosimeters: Questions to be discussed
• Limited sensitivity
• Cross talk between different frequency bands
• Measurement accuracy
- Isotropicity
- Influence of the user
- Response to modulated signals
- Summation of multiple signals in the same band
• Functional and ergonomic aspects
¾ Dosimeters seem to be very helpful for epi-studies,
(although their quality need to be investigated in detail)
Folie 37
Summary and conclusion
• Relevant exposures are:
- mobile phone base stations (GSM+UMTS) and mobile phones
- digital and analogue radio and TV broadcast
- Wireless LAN and DECT cordless phones
• Most services exhibit strong time variations (power control) and
space variations (fast fading)
→ worst case exposure differs from averaged exposure
• General comparison of exposures show:
- Strongest exposure by sources near to body/body contact
- Long/Medium/Shortwave radio service often underestimated
• Dosimeters seem to be very helpful for epi-studies,
(although their quality need to be investigated in detail)
Folie 38

Exposure of the general public to RF electromagnetic fields

Transcription

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